Foundation Engineering (CE-802 (B)) - Important Questions

Explain the Standard Penetration Test (SPT) procedure, the meaning of N-value, why corrections are needed, and explain the overburden and dilatancy corrections applied to observed N.

Explain boring methods for subsurface exploration including rotary drilling technique with neat sketch and discuss its advantages over other methods.

Explain the various types of foundations/footings with neat sketches, their applications and basic criteria for satisfactory performance.

Explain representative and undisturbed sampling. Describe soil samplers, area ratio and inside/outside clearance requirements for good quality undisturbed samples.

Describe the different modes of shear failure in soils beneath shallow foundations - general, local and punching shear - with neat sketches.

A strip footing 2 m wide is founded at 1.5 m depth in sand having unit weight 18 kN/m3 and phi = 30 degrees. Using Terzaghi's theory with Nc=30.1, Nq=18.4, Ngamma=15.1, calculate the ultimate bearing capacity and total allowable load per metre run for FS=3.

A 2 m x 3 m rectangular footing carries 600 kN at 1 m depth on a 6 m thick soil stratum having Poisson's ratio 0.25 and Young's modulus 8000 kN/m2. Calculate the immediate elastic settlement of the footing.

A 400 mm diameter pile 18 m long is driven in uniform clay with cohesion 60 kN/m2 and adhesion factor 0.7. Determine the ultimate load carrying capacity of the pile using static formula considering skin friction and end bearing.

A 3x3 friction pile group of 300 mm diameter, 10 m long piles at 0.9 m c/c spacing is embedded in soft clay with cohesion 70 kN/m2. Neglecting end bearing, calculate the ultimate and safe capacity of the group using adhesion factor, including block failure check.

What is negative skin friction in piles? Explain its causes, effects on pile capacity and measures to reduce it.

Discuss the problems of foundations on expansive and collapsible soils and explain the preventive measures adopted for construction on such soils.

Explain the types, functions and various uses of geosynthetics for soil improvement and foundation engineering.

A retaining wall retains 3 m of sand with gamma=16 kN/m3, phi=28 degrees overlying 4 m of sand with gamma=20 kN/m3, phi=34 degrees. Determine the total Rankine active earth thrust, its magnitude and point of application.

Explain the classification, functions and modes of failure of retaining walls and the design checks for stability against overturning, sliding and bearing capacity failure.

Compare Rankine's and Coulomb's earth pressure theories. Discuss assumptions, limitations and merits of Coulomb's theory over Rankine's theory.